KR102542652B1 - Vehicle steering system for efficient vehicle driving in various driving environments - Google Patents

Abstract

Embodiments include a front wheel module 100 configured to steer the front wheels of the vehicle through the rotational power of the first motor 101, and a rear wheel module configured to steer the rear wheels of the vehicle through the rotational power of the second motor 201 ( 200), the longitudinal axis module configured to connect the front wheel module 100 and the rear wheel module 200 and to inwardly steer the left and right wheels of the front wheel and the left and right wheels of the rear wheel through the rotational power of the third motor 300, respectively. 300, and a controller 400 for controlling the first to third motors and a driving motor that provides rotational power to at least one of the front and rear wheels, and a steering wheel installed in a vehicle having front and rear wheels. It's about the system.

Description

Vehicle steering system for efficient vehicle driving in various driving environments}

Embodiments of the present application relate to a vehicle steering system for efficiently driving a vehicle in various driving environments.

In response to the severity of environmental problems caused by the use of fossil fuels such as gasoline and diesel and the depletion of limited resources, eco-friendly vehicles such as electric vehicles, fuel cell vehicles, and hybrid vehicles driven by motors are being developed and operated.

The in-wheel system is a system in which small individual motors (in-wheel motors) are mounted inside the wheels of an eco-friendly vehicle that uses electricity as a power source to independently and directly control each wheel.

The in-wheel system is equipped with individual motors inside the wheels of each wheel, so the drive system is simple compared to cars with large drive motors, and the space utilization is excellent. It is possible to improve the behavioral performance of the vehicle.

In addition, steering by driving is possible by generating lateral force by adjusting the torque difference between the left and right wheels, and has the advantage of being able to omit complicated power transmission devices such as transmissions or differentials.

However, conventional in-wheel systems can only turn left or right, and thus have limitations in efficiently coping with various driving environments.

Patent Publication No. 10-2013-0012827 (2013.02.05.)

Based on the discussion as described above, embodiments of the present application are intended to provide a vehicle steering system for efficiently driving a vehicle in various driving environments by enabling left and right turns as well as left / right diagonal directions and turning in place. do.

A steering system installed in a vehicle having front and rear wheels according to an aspect of the present application includes a front wheel module 100 configured to steer the front wheels of the vehicle through rotational power of a first motor 101, and a second motor 201 ) The rear wheel module 200 configured to steer the rear wheels of the vehicle through the rotational power of the vehicle, the front wheel module 100 and the rear wheel module 200 are connected, and the rotational power of the third motor 300 of the vehicle A controller for controlling a longitudinal axis module 300 configured to inwardly steer the left and right wheels of the front wheel and the left and right wheels of the rear wheel, respectively, and the first to third motors and a driving motor that provides rotational power to at least one of the front and rear wheels. (400).

In one embodiment, the front wheel module is installed between the left wheel 11 and the right wheel 12 of the front wheel, and moves to the left or right by the rotational power of the first motor 101 to steer the front wheel. A rack and pinion 130 having a rack 131 that is connected to one end of the front links 151 and 152 through both ends of the rack and pinion 130 and joints 141 and 142, the front links 151 and 152, It may include base frames 171 and 172 connected to the other ends of the front links 151 and 152 through joints 161 and 162 and supporting the left wheel 11 and the right wheel 12 of the front wheel. The rear wheel module 200 is a rack that is installed between the left wheel 21 and the right wheel 22 of the rear wheel and moves to the left or right by the rotational power of the second motor 201 to steer the rear wheel ( 231), the rear links 251 and 252 connected to both ends of the rack and pinion 230 and one end of the rear links 251 and 252 through joints 241 and 242, the rear link It may include base frames 271 and 272 connected to the other ends of 251 and 252 through joints 261 and 262 and supporting the left wheel 21 and the right wheel 22 of the rear wheel.

The joints 161 and 162 are the front links 151 and 152 and the base frames 171 and 172 so that the rack 131 turns in relation to the coupling axis when a steering control force generated by moving the rack 131 in the left or right direction is applied. combined with The joints 261 and 262 are connected to the rear links 251 and 252 and the base frames 271 and 272 so that the rack 231 pivots with respect to a coupling axis when a steering control force generated by moving the rack 231 in the left or right direction is applied. combined with

In one embodiment, in order to control the vehicle to turn left, the controller 400 rotates the first motor 101 in a first rotation direction so that the rack 131 moves in a left direction. To supply a -1 control command to the first motor 101, and to control the vehicle to turn right, the first motor 101 rotates in a second rotation direction opposite to the first rotation direction, It may be configured to supply the first motor 101 with a 1-2 control command for moving the rack 131 in the right direction.

In one embodiment, the controller 400 rotates the second motor 201 in the second rotation direction so that the left turning radius of the vehicle is smaller than when only the front wheels or only the rear wheels are steered, so that the rack ( 231) supplies a 2-2 control command to move in the left direction to the second motor 201, and so that the right turning radius of the vehicle is reduced compared to the case of steering only the front wheels or only the rear wheels, the second motor 201 The motor 201 may be further configured to rotate in the second rotation direction to supply the second motor 201 with a 2-1 control command to move the rack 231 in the right direction.

In one embodiment, the controller 400 rotates the first motor 101 in a first rotational direction so that the rack 131 moves leftward so that the vehicle travels in a diagonal direction to the left. 1-1 control command is supplied to the first motor 101, and the second motor 201 rotates in a second rotation direction opposite to the first rotation direction, so that the rack 131 moves to the right. In order to supply the second motor 201 with a 2-2 control command to move in the right diagonal direction, and to control the vehicle to travel in the right diagonal direction, the first motor 101 is configured to move in the second rotation direction. 1-2 control commands for causing the rack 131 to move in the right direction are supplied to the first motor, and the second motor 201 rotates in the first rotation direction to rotate the rack 131 in the right direction. ) may be configured to supply the second motor 201 with a 2-1 control command to move in the left direction. A steering angle according to the 1-1 control command and a steering angle according to the 2-2 control command are parallel to each other. A steering angle according to the 1-2 control command and a steering angle according to the 2-1 control command are parallel to each other.

In one embodiment, when the rack 131 moves in the left or right direction, the joints 141 and 142 do not turn based on the coupling axis and apply steering control force according to the movement of the rack 131 to the front link 151. , 152) is coupled to the rack and pinion 130 and the front links 151 and 152 so as to be transmitted to the base frames 171 and 172, and the joints 241 and 242 allow the rack 231 to be left or right When moving in the direction, the rack and pinion 230 and the rear link transmit the steering control force according to the movement of the rack 231 to the base frames 271 and 272 through the rear links 251 and 252 without turning with respect to the coupling axis (251, 252) can be combined.

In one embodiment, the vertical axis module 300, the ball screw 331 coupled with the third motor 301 to rotate the ball screw 331 according to the rotational power of the third motor 301, When the ball screw 331 rotates, the ball screw 331 moves along an extended axis, and the ball screw case 341 coupled with the ball screw 331 - the ball screw case 341 is the ball screw 331 The rack and pinion 130 is coupled to the rack and pinion 130 so as to move along the extended axis according to the rotation of the ball screw coupled to rotate the ball screw 332 according to the rotation of the ball screw 331 332, the ball screw case 342 coupled with the ball screw 332 so that the ball screw 332 moves along an extended axis when the ball screw 332 rotates - the ball screw case 342 Combined with the rack and pinion 230 so that the rack and pinion 230 moves along the extended shaft as the ball screw 332 rotates.

In one embodiment, the rack and pinions 130 and 230 are coupled to the extension shafts of the ball screws 331 and 332 at right angles. When the third motor 301 rotates in the first rotational direction, the base frames 171 and 172 of the front wheel module 100 do not turn with respect to the joints 161 and 162 and the base frames 171 and 172 ) and the front links 151 and 152 are fixed, and one end of the front links 151 and 152 connected to the rack and pinion 130 pivots and moves based on the joints 141 and 142, so that the front Links 151 and 152 are arranged diagonally in the plane of the vehicle. In the rear wheel module 200, the base frames 271 and 272 do not turn based on the joints 261 and 262, and the angle between the base frames 271 and 272 and the rear links 251 and 252 is fixed, and the rack and One ends of the rear links 251 and 252 connected to the pinion 230 pivot and move with respect to the joints 241 and 242, so that the rear links 251 and 252 move on the plane of the vehicle. 151, 152) are arranged diagonally symmetrically.

In one embodiment, in order to control the vehicle to turn in place, the controller 400 gives a 3-1 control command for rotating the third motor 301 in a first rotation direction to the third motor ( 301), and transmits a forward control command or a reverse control command to the drive motor in a state in which the arrangement structure of the front links 151 and 152 and the rear links 251 and 252 are arranged diagonally to each other. Can be configured to transmit there is.

In one embodiment, the controller 400 stops the vehicle by stopping transmission of the forward control command or the reverse control command when the vehicle turns in place by 90 °, and the front links arranged in a diagonal state ( 151, 152 and rear links 251, 252 in parallel with the rack and pinion 130, 230, the third motor 301 rotates in the second rotation direction opposite to the first rotation direction. It may be further configured to transmit a 3-2 control command to rotate to the third motor 301 .

An autonomous vehicle according to another aspect of the present application may include a steering system according to the above-described embodiments, and an in-wheel motor installed on at least one of the left and right wheels of the front and rear wheels. The base frames 171 , 172 , 271 , and 272 are coupled to the in-wheel motors 110 , 120 , 210 , and 220 .

A steering system of a vehicle according to various embodiments of the present disclosure is configured to enable right steering, left steering, and inward steering of at least one pair of front and rear wheels of a vehicle. Accordingly, the vehicle equipped with the steering system can not only turn left and right, but also drive in left/right diagonal directions and turn in place.

As a result, the steering system can effectively drive the vehicle without collision in various driving environments having various widths and curvatures.

The effects obtainable in the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below. will be

In order to more clearly describe the technical solutions of the embodiments of the present invention or the prior art, drawings necessary in the description of the embodiments are briefly introduced below. It should be understood that the drawings below are for the purpose of explaining the embodiments of the present specification and not for the purpose of limitation. In addition, for clarity of explanation, some elements applied with various modifications, such as exaggeration and omission, may be shown in the drawings below.
1 is a configuration diagram of a steering system of a vehicle according to an aspect of the present application.
2A and 2B illustrate a control operation of a front wheel module according to various embodiments of the present application.
3A and 3B illustrate a control operation of a rear wheel module according to various embodiments of the present application.
FIG. 4 describes a situation in which a vehicle travels on a general curved path according to the control operation of FIG. 2 .
5A and 5B describe a control operation for traveling in a more rapid rotation by steering the front and rear wheels according to various embodiments of the present application.
FIG. 6 describes a situation in which a vehicle travels a curved path having a shorter radius of curvature than a normal curved path according to the control operation of FIG. 5 .
7A and 7B describe a control operation for diagonal driving by steering the front and rear wheels according to various embodiments of the present application.
FIG. 8 describes a situation in which the vehicle travels diagonally according to the control operation of FIG. 7 .
9a and 9b illustrate a control operation of a vertical axis module according to various embodiments of the present application.
FIG. 10 describes a situation in which a 180° zero-turn is performed according to the control operation of FIG. 9 .
FIG. 11 describes a situation in which a 90 degree turns in place according to the control operation of FIG. 9 .
12 is a flowchart of a steering method according to another aspect of the present application.

Hereinafter, with reference to the drawings, look at the embodiments of the present invention in detail.

However, it should be understood that this disclosure is not intended to limit the disclosure to specific embodiments, and includes various modifications, equivalents, and/or alternatives of the embodiments of the disclosure. . In connection with the description of the drawings, like reference numerals may be used for like elements.

In this specification, expressions such as “has,” “can have,” “includes,” or “can include” refer to corresponding characteristics (eg, numerical values, functions, operations, steps, parts, elements, and/or components). elements), and does not preclude the presence or addition of additional features.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Expressions such as “first”, “second”, “first” or “second” used in various embodiments may modify various elements regardless of order and/or importance, and limit the elements. I never do that. The above expressions may be used to distinguish one component from another. For example, the first element and the second element may represent different elements regardless of order or importance.

Embodiments of a singular expression used in this specification also include embodiments of a plural expression unless the phrases related to the singular expression clearly indicate the opposite meaning.

As used herein, the expression “configured to (or configured to)” means, depending on the situation, for example, “suitable for”, “having the capacity to” ,” “designed to,” “adapted to,” “made to,” or “capable of.” The term “configured (or set) to” may not necessarily mean only “specifically designed to” hardware. Instead, in some contexts, the expression "device configured to" may mean that the device is "capable of" in conjunction with other devices or components. For example, the phrase "a processor configured (or set) to perform A, B, and C" may include a dedicated processor (e.g., embedded processor) to perform those operations, or one or more software programs stored in a memory device. By doing so, it may mean a general-purpose processor (eg, CPU or application processor) capable of performing corresponding operations.

Terms including technical or scientific terms used in the present invention may have the same meaning as commonly understood by a person of ordinary skill in the technical field described in the present invention. Among the terms used in the present invention, terms defined in a general dictionary may be interpreted as having the same or similar meaning as the meaning in the context of the related art, and unless explicitly defined in the present invention, an ideal or excessively formal meaning not be interpreted as In some cases, even terms defined in the present invention cannot be interpreted to exclude embodiments of the present invention.

In this specification, inside indicates the direction inside the vehicle and outside indicates the direction outside the vehicle. When the front wheel of the vehicle turns left, the left wheel of the front wheel rotates outward and the right wheel rotates inward.

1 is a configuration diagram of a steering system of a vehicle according to an aspect of the present application.

The vehicle steering system 10 may be installed in a vehicle having front and rear wheels.

The vehicle is not limited to a car that can be boarded by a person, and refers to a transportation means that can be used in the construction field, agriculture field, landscaping field, and military field, which can be described below. For example, the vehicle may be a small unmanned vehicle capable of remotely controlling driving, such as a lawn mower or an unmanned delivery robot.

In various embodiments of the present application, the vehicle may be an in-wheel motor-driven vehicle in which the in-wheel motors 110, 120, 210, and 220 are installed. A driving motor providing rotational power to at least one of the front and rear wheels is implemented as an in-wheel motor.

The in-wheel motors 110, 120, 210, and 220 are coupled to the inside of the left and right wheels 11, 12, 21, and 22 of the front and rear wheels and are installed on the vehicle body by a suspension arm. In the above embodiments, that a specific component is connected to a wheel such as a front wheel or a rear wheel means that it is connected to the in-wheel motor 110, 120, 210, or 220 installed inside the wheel.

In-wheel motors known at the time of filing of the present application, which can be mounted on electric vehicles, can be utilized as various in-wheel motors 110, 120, 210, and 220.

Also, referring to FIG. 1 , the steering system 10 of the vehicle includes a front wheel module 100 configured to steer the front wheels of the vehicle through rotational power of a first motor 101; a rear wheel module 200 configured to steer the rear wheels of the vehicle through rotational power of a second motor 201; a longitudinal axis module 300 configured to inwardly steer the front and rear wheels of the vehicle through rotational power of a third motor 301; and a controller 400 controlling the first to third motors 101, 201, and 301.

Controller 400 includes a processor and memory. The controller 400 controls the first to third motors 101 , 201 , and 301 to generate rotational power of the control target motor 101 , 201 , or 301 . In addition, the controller 400 is configured to control a driving motor that provides rotational power to at least one of the front and rear wheels, such as the in-wheel motors 110, 120, 210, and 220.

The controller 400 may be implemented as an engine control unit (ECU) built into a vehicle and controlling components inside the vehicle by wire. However, it is not limited thereto, and may be implemented as a separate controller from the ECU according to embodiments.

In some embodiments, upon receiving steering target angle information and target torque information, the controller 400 outputs torque to be applied to the in-wheel motors 110, 120, 210, and 220 according to the steering target angle information and target torque information. It may be further configured to calculate and control the operation of the in-wheel motors 110, 120, 210, and 220.

In some embodiments, the controller 400 may receive the steering target angle information and target torque information from a sensor installed in a vehicle's steering wheel to detect steering manipulation information. The target steering angle and target torque may be input to the controller 400 by manipulating the steering wheel.

In some other embodiments, the vehicle may be an autonomous vehicle in which an autonomous driving program is installed. Then, the controller 400 may receive steering target angle information and target torque information for each position on the driving route from an external device connected to the controller 400 through wired/wireless telecommunication. When receiving an autonomous driving command from an external input device, the controller 400 may receive steering target angle information and target torque information through the autonomous driving command.

In some other embodiments, the vehicle or steering system 10 may further include a component for autonomous driving. The vehicle or steering system 10 includes a recognition device capable of recognizing an obstacle on a driving path. The recognition device may include one or more of a lidar sensor, an image sensor, a camera module, and other sensors capable of recognizing an obstacle. The self-driving program includes a command that analyzes an image captured by a recognition device and causes the controller 400 to control at least one module 100, 200, or 300.

First, the operation of the front wheel module 100 will be described.

2A and 2B illustrate a control operation of a front wheel module according to various embodiments of the present application.

2A and 2B, the front wheel module 100 includes a rack and pinion 130 installed between the left wheel 11 and the right wheel 12 of the front wheel, both ends of the rack and pinion 130 and a joint 141 , 142) to the front links 151 and 152 to which one end of the front links 151 and 152 is connected, and the other end and one end of the front links 151 and 152 to be connected through joints 161 and 162, It includes base frames 171 and 172 supporting the left wheel 11 and the right wheel 12 of the front wheel.

The first motor 101 operates as a front wheel steering motor. When receiving a control command from the controller 400, the first motor 101 is driven according to the control command to generate rotational power for steering the front wheels to the left or right. The first motor 101 is coupled to the pinion gear of the rack and pinion 130 below, and supplies rotational power to the pinion gear of the rack and pinion 130.

The rack and pinion 130 is installed between the in-wheel motors 110 and 220. In some embodiments, the rack and pinion 130 may be installed on a center link connecting the front links 151 and 152.

The rack and pinion 130 has a rack gear 131 (hereinafter referred to as “rack”) that moves left or right by rotational power of the first motor 101 to steer the front wheels. Specifically, the rack and pinion 130 has a rack gear 131 and a pinion gear. The rack and pinion 130 is configured to move the rack 131 to the left or right when rotational power of the first motor 101 drives the pinion gear. When the first motor 101 rotates in a first rotational direction, the rack 131 moves to the left, and when it rotates in a second rotational direction opposite to the first rotational direction, the rack 131 can move to the right. . The first rotation direction may be set to clockwise or counterclockwise.

The front links 151 and 152 connect between the rack and pinion 130 and the base frames 171 and 172 so as to transmit a steering control force according to the movement of the rack 131 to the base frames 171 and 172.

When the rack 131 moves in the left or right direction, the joints 141 and 142 do not rotate with respect to the coupling axis and apply steering control force according to the movement of the rack 131 to the base frame through the front links 151 and 152 ( 171 and 172 are coupled to the rack and pinion 130 and the front links 151 and 152.

As described in FIG. 9 below, the joints 141 and 142 connect the rack and pinion 130 through the joints 141 and 142 when the rack and pinion 130 moves toward the front or rear of the vehicle. The connected front links 151 and 152 are coupled to move in the longitudinal direction of the vehicle according to the movement of the rack and pinion 130 . The joints 141 and 142 may be implemented as a hinge joint structure connecting both ends of the rack and pinion 130 and one end (ie, an inner end) of the front links 151 and 152. . In some embodiments, the steering angles of the joints 141 and 142 may depend on the extension lengths of the ball screw cases 341 and 342, which will be described in FIG. 9 below.

The base frames 171 and 172 are coupled to the in-wheel motors 110 and 120 to support the left wheel 11 and the rear wheel 12 of the front wheel. The steering control force according to the left or right movement of the rack 131 is transmitted to the in-wheel motors 110 and 120 and the left/right wheels 210 and 220 of the rear wheels through the base frames 171 and 172. When the base frames 171 and 172 turn with respect to the joints 161 and 162, the in-wheel motors 110 and 120 and the left and right wheels 110 and 120 of the front wheels coupled thereto rotate with respect to the base frames 171 and 172. Steer according to the direction of the turn.

The joints 161 and 162 have the other end (ie, the outer end) of the front links 151 and 152 so that the rack 131 turns with respect to the coupling axis when a steering control force generated by moving in the left or right direction is applied. ) And combined with the base frame (171, 172). The joints 161 and 162 are coupled to the front links 151 and 152 and the base frames 171 and 172 so that the base frames 171 and 172 turn at a predetermined steering angle.

3A and 3B illustrate a control operation of a rear wheel module according to various embodiments of the present application.

3A and 3B, the rear wheel module 200 includes a rack and pinion 230 installed between the left wheel 21 and the right wheel 22 of the rear wheel, both ends of the rack and pinion 230 and a joint 241 The rear links 251 and 252 connected to one end of the rear links 251 and 252 through , 242 and the other end of the rear links 251 and 252 through joints 261 and 262, of the rear wheel It includes base frames 271 and 272 supporting the left wheel 21 and the right wheel 22 .

The second motor 201 operates as a rear wheel steering motor. When the second motor 201 receives a control command from the controller 400, it is driven according to the control command to generate rotational power for steering the rear wheels to the left or right. The second motor 201 is coupled to the pinion gear of the rack and pinion 230 below, and supplies rotational power to the pinion gear of the rack and pinion 230.

The rack and pinion 230 is installed between the in-wheel motors 210 and 220. In some embodiments, the rack and pinion 130 may be installed on a center link connecting the front links 151 and 152. The rack and pinion 230 has a rack gear 231 (hereinafter referred to as “rack”) that moves left or right by rotational power of the second motor 201 to steer the rear wheels. Specifically, the rack and pinion 230 has a rack gear 231 and a pinion gear. The rack and pinion 230 is configured to move the rack 231 left or right when rotational power of the second motor 201 drives the pinion gear.

In some embodiments, the second motor 201 and the first motor 101 may be installed such that planar structures of the front wheel module 100 and the rear wheel module 200 are symmetrical to each other. As shown in FIG. 2 , the first motor 101 may be installed closer to the center of the vehicle than the rack and pinion 130, and the second motor 201 may also be installed closer to the center of the vehicle than the rack and pinion 230. there is.

A control command for rotating in the same rotation direction from the controller 400 is supplied to the first motor 101 and the second motor 201 so that the first motor 101 and the second motor 201 rotate in the same rotation direction. , the rack 131 connected to the first motor 101 and the rack 231 connected to the second motor 201 may move in opposite directions. For example, when the first motor 101 rotates in the first rotational direction, the rack 131 moves to the left, and when the second motor 201 rotates in the first rotational direction, the rack 231 moves to the right. there is. Alternatively, when the first motor 101 rotates in a second rotation direction opposite to the first rotation direction, the rack 131 moves to the right and the second motor 201 rotates in the second rotation direction. When the rack 231 can be moved to the left.

The rear links 251 and 252 connect between the rack and pinion 230 and the base frames 271 and 272 so as to transmit a steering control force according to the movement of the rack 231 to the base frames 271 and 272 .

When the rack 231 moves in the left or right direction, the joints 241 and 242 do not turn with respect to the coupling axis, and the steering control force according to the movement of the rack 231 is applied to the base frame through the rear links 251 and 252 ( 271 and 272 are combined with the rack and pinion 230 and the rear links 251 and 252.

As described in FIG. 9 below, the joints 241 and 242 connect the rack and pinion 230 through the joints 241 and 242 when the rack and pinion 230 moves toward the front or rear of the vehicle. The connected rear links 251 and 252 are coupled to move in the longitudinal direction of the vehicle according to the movement of the rack and pinion 230 . The joints 241 and 242 may be implemented as a hinge joint structure connecting both ends of the rack and pinion 230 and one end (ie, inner end) of the rear links 251 and 252. . In some embodiments, the steering angles of the joints 241 and 242 may depend on the extension lengths of the ball screw cases 341 and 342, which will be described in FIG. 9 below.

The base frames 271 and 272 are coupled to the in-wheel motors 210 and 220 to support the left wheel 21 and the rear wheel 22 of the rear wheel. Steering control force according to left or right movement of the rack 231 is transmitted to the in-wheel motors 210 and 220 and the left/right wheels 210 and 220 of the rear wheels through the base frames 271 and 272. When the base frames 271 and 272 turn with respect to the joints 261 and 262, the in-wheel motors 210 and 220 and the left and right wheels 210 and 220 of the rear wheels coupled thereto rotate along the base frames 271 and 272. Steer according to the direction of the turn.

The joints 261 and 262 are connected to the rear links 251 and 252 and the base frames 271 and 272 so that the rack 231 pivots with respect to a coupling axis when a steering control force generated by moving the rack 231 in the left or right direction is applied. combined with The joints 261 and 262 are coupled to the rear links 251 and 252 and the base frames 271 and 272 so that the base frames 271 and 272 turn by a predetermined steering angle.

The controller 400 transmits a control command to the first motor 101 to control the steering operation of the front wheel module 100 or transmits a control command to the second motor 201 to control the steering of the rear wheel module 200. You can control the action. The controller 400 may control the steering operation of the front wheel module 100 or the rear wheel module 200 for left turn or right turn driving of the vehicle. In addition, the controller 400 may control the steering operation of the front wheel module 100 or the rear wheel module 200 for left turn reverse or right turn reverse of the vehicle.

In some embodiments, the controller 400 is a 1-1 control for moving the rack 131 in the left direction by rotating the first motor 101 in the first rotation direction so that the vehicle turns left. A command is supplied to the first motor 101 or the second motor 201 rotates in a second rotation direction opposite to the first rotation direction so that the rack 231 moves in the right direction. 2-2 control command is configured to supply the second motor (201).

For example, when the 1-1 control command is supplied to the first motor 101, as shown in FIG. 162), the in-wheel motors 110 and 120 and the left/right wheels 11 and 12 of the front wheels are steered so that the vehicle turns left. Alternatively, when the 2-2 control command is supplied to the motor 201, as shown in FIG. 3A, the rack 231 moves to the right so that the base frames 271 and 272 are relative to the joints 261 and 262. As a result, the in-wheel motors 210 and 220 and the left/right wheels 21 and 22 of the rear wheels are steered so that the vehicle turns left.

In addition, the controller 400 causes the first motor 101 to rotate in a second rotation direction opposite to the first rotation direction so that the rack 131 moves rightward in order for the vehicle to turn right. supplying a 1-2 control command to the first motor 101 or causing the second motor 201 to rotate in the first rotational direction so that the rack 231 moves leftward; 1 control command is configured to supply the second motor (201).

For example, when the 1-2 control commands are supplied to the first motor 101, as shown in FIG. 162), the in-wheel motors 110 and 120 connected to the base frames 171 and 172 and the left/right wheels 11 and 12 of the front wheels are steered so that the vehicle turns right. Alternatively, when the 2-1 control command is supplied to the motor 201, as shown in FIG. 3B, the rack 231 moves to the right so that the base frames 271 and 272 are relative to the joints 261 and 262. Then, the in-wheel motors 210 and 220 connected to the base frames 171 and 172 and the left/right wheels 21 and 22 of the rear wheels steer the vehicle to turn right.

In some embodiments, the maximum turning angle range of the base frame 171 and the base frame 271 may be the same. Then, the turning radius of the vehicle according to the 1-1 control command and the turning radius of the vehicle according to the 2-2 control command may be the same. Also, in some embodiments, the maximum turning angle range of the base frame 172 and the base frame 272 may be the same. Then, the turning radius of the vehicle according to the 1-2 control command and the turning radius of the vehicle according to the 2-1 control command may be the same.

FIG. 4 describes a situation in which a vehicle travels on a general curved path according to the control operation of FIG. 2 .

When the vehicle drives on a general curved path that cannot be driven without deviation at a steering angle within the maximum steering angle range of the front wheels, the controller 400 drives the first motor 101 to drive the left/right wheels 11, 12) can be steered. When the controller 400 supplies 1-2 control commands to the first motor 101 while traveling on a general curved path having a radius of curvature R1 shown in FIG. can drive

Also, although not shown, the controller 400 may drive the first motor 101 to steer the left/right front wheels 11 and 12 so that the vehicle moves backward on a general curved path.

In addition, the controller 400 can control the first motor 101 and the second motor 201 to enable more rapid rotation with a shorter turning radius than when only the front wheels or rear wheels of the vehicle are steered. .

5A and 5B describe a control operation for driving in a more rapid rotation by steering the front and rear wheels according to various embodiments of the present application, and FIG. 6 illustrates a vehicle moving along a general curved path according to the control operation of FIG. 5 . A situation of traveling on a curved path with a shorter radius of curvature will be described.

5A and 5B, the controller 400 transmits a control command to the first motor 101 to control the steering operation of the front wheel module 100 and to the second motor 201. A steering operation of the rear wheel module 200 may be controlled by transmitting a command. When the first motor 101 and the second motor 201 simultaneously provide rotational power, the turning radius of the vehicle is further reduced. The steering operation of the rear wheel module 200 for such rapid rotation is to rotate in the same direction as the direction in which the vehicle rotates according to the steering operation of the front wheel module 100 .

In some embodiments, the controller 400 rotates the first motor 101 in a first rotation direction so that the left turning radius of the vehicle in which the steering system 10 of FIG. 1 is installed is further reduced, so that the rack ( 131) supplies the 1-1 control command to move in the left direction to the first motor 101, and the second motor 201 rotates in a second rotation direction opposite to the first rotation direction It is configured to supply the second motor 201 with the 2-2 control command for moving the rack 231 in the right direction.

For example, when the 1-1 control command and the 2-2 control command are supplied to the motors 101 and 201, as shown in FIG. 5A, the rack 131 moves to the left and the base frame 171 , 172) rotates based on the joints 161 and 162 and the rack 231 moves to the right so that the base frames 271 and 272 rotate based on the joints 261 and 262, and eventually the in-wheel motor 110 , 120, 210, 220) and left/right wheels 11, 12, 21, 22 of the front and rear wheels are steered so that the vehicle turns left more rapidly.

In addition, the controller 400 rotates the first motor 101 in a second rotation direction opposite to the first rotation direction so that the rack 131 moves in the right direction so that the right turning radius of the vehicle is further reduced. Supplying the 1-2 control command to move to the first motor 101 and rotating the second motor 201 in the first rotation direction to move the rack 231 in the left direction It is configured to supply the 2-1 control command to the second motor (201).

For example, when the 1-2 control commands are supplied to the first motor 101, as shown in FIG. 162), the in-wheel motors 110 and 120 connected to the base frames 171 and 172 and the left/right wheels 11 and 12 of the front wheels are steered so that the vehicle turns right. Alternatively, when the 2-1 control command is supplied to the motor 201, as shown in FIG. 3B, the rack 231 moves to the right so that the base frames 271 and 272 are relative to the joints 261 and 262. Then, the in-wheel motors 210 and 220 connected to the base frames 171 and 172 and the left/right wheels 21 and 22 of the rear wheels steer the vehicle to turn right.

The steering angle according to the 1-1 control command and the steering angle according to the 2-2 control command may be the same or different. Also, the steering angle according to the 1-2 control command and the steering angle according to the 2-1 control command may be the same as or different from each other.

As a result, the left/right wheels 11 and 12 of the front wheels steer to the left and the left and right wheels 21 and 22 of the rear wheels steer to the right at the same time, so that the left turning radius or the right turning radius of the vehicle steers only the front wheels or only the rear wheels. It decreases when steering. As a result, as shown in FIG. 6, when only the front wheels are steered or only the rear wheels are steered with a radius of curvature (R2, R1>R2) shorter than that of the general driving route, it is possible to stably drive a specific driving route without deviation. can

Also, the controller 400 may control the first motor 101 and the second motor 201 for diagonal driving of the vehicle.

7A and 7B describe a control operation for diagonal driving by steering front and rear wheels according to various embodiments of the present application. FIG. 8 describes a situation in which the vehicle travels diagonally according to the control operation of FIG. 7 .

7A and 7B, the controller 400 transmits a control command to the first motor 101 to control the steering operation of the front wheel module 100 and to the second motor 201. A steering operation of the rear wheel module 200 may be controlled by transmitting a command. When the first motor 101 and the second motor 201 simultaneously provide rotational power, the vehicle may travel diagonally. Here, the steering operation of the rear wheel module 200 for diagonal driving and the steering operation of the front wheel module 100 may be operations that have parallel steering angles.

In some embodiments, the controller 400 rotates the first motor 101 in a first rotational direction so that the rack 131 moves leftward so that the vehicle travels in a diagonal direction to the left. 1-1 control command is supplied to the first motor 101, and the second motor 201 rotates in a second rotation direction opposite to the first rotation direction, so that the rack 131 moves to the right. It may be configured to supply the second motor 201 with a 2-2 control command to move in the direction. Here, the steering angle according to the 1-1 control command and the steering angle according to the 2-2 control command are parallel to each other. The steering angle is an angle formed by the steered wheel from a reference line extending along the rack and pinion (130, 230).

Then, as shown in FIG. 7A, the rack 131 moves to the left, and the base frames 171 and 172 rotate based on the joints 161 and 162, so that the in-wheel motor connected to the base frames 171 and 172 ( 110, 120) and the left/right wheels 11, 12 of the front wheels are steered toward the left diagonal. In addition, as the rack 231 moves to the right, the base frames 271 and 272 rotate based on the joints 261 and 262, and eventually the in-wheel motors 210 and 220 connected to the base frames 171 and 172 and the rear wheels The left/right wheels 21 and 22 of are steered toward the left diagonal.

In addition, the controller 400 rotates the first motor 101 in the second rotation direction to control the vehicle to drive in the right diagonal direction so that the rack 131 moves in the right direction. The 2-1 control command for supplying a 1-2 control command to the first motor and causing the second motor 201 to rotate in the first rotation direction to move the rack 131 in the left direction is as described above. It may be configured to supply to the second motor 201 . Here, the steering angle according to the 1-2 control command and the steering angle according to the 2-1 control command are parallel to each other.

Then, as shown in FIG. 7B, the rack 131 moves to the right, and the base frames 171 and 172 rotate based on the joints 161 and 162, so that the in-wheel motor connected to the base frames 171 and 172 ( 110, 120) and the left/right wheels 11, 12 of the front wheels are steered toward the right diagonal. In addition, as the rack 231 moves to the right, the base frames 271 and 272 rotate based on the joints 261 and 262, and eventually the in-wheel motors 210 and 220 connected to the base frames 171 and 172 and the rear wheels The left/right wheels 21 and 22 of are steered toward the right diagonal.

As a result, as shown in FIG. 8 , the vehicle can travel on a non-rotatable path in a diagonal manner without collision.

In addition, the controller 400 may control the third motor 301 of the vertical axis module 300 to zero-turn the vehicle.

9a and 9b illustrate a control operation of a vertical axis module according to various embodiments of the present application.

The longitudinal axis module 300 is configured along the longitudinal axis of the vehicle to connect the front wheel module 100 and the rear wheel module 200. The longitudinal axis module 300 is configured to steer the left and right wheels 11 and 12 of the front wheels and the left and right wheels 21 and 22 of the rear wheels of the vehicle through rotational power of the third motor 301, respectively. Specifically, the longitudinal axis module 300 moves the front wheel module 100 and the rear wheel module 200 partially along the longitudinal axis through the rotational power of the third motor 301, eventually moving the front and rear wheels of the vehicle to the inside. It is configured to steer.

The third motor 301 operates as a motor for inward steering of the front and rear wheels. Inward steering of the front wheels is steering such that the front of each of the left/right wheels 11 and 12 of the front wheels narrows toward the inside and the rear thereof widens toward the outside. The inward steering of the rear wheel is steered symmetrically with the inward steering of the front wheel, and is steered such that the front of each of the left and right wheels 21 and 22 of the rear wheel widens toward the outside and the rear wheel narrows toward the inside.

In various embodiments of the present application, the longitudinal axis module 300 is configured to simultaneously inwardly steer the front and rear wheels when the third motor 301 rotates in the first direction. Specifically, the longitudinal axis module 300 is a third motor 301 for generating rotational power, the third motor 301 and the third motor 301 so that the ball screw 331 rotates according to the rotational power of the third motor 301 The coupled ball screw 331, the ball screw case 341 coupled with the ball screw 331 so that the ball screw 331 moves along an extended axis when the ball screw 331 rotates, and the ball screw 331 ), the ball screw 332 is coupled to rotate according to the rotation of the ball screw 332, and when the ball screw 332 rotates, the ball screw 332 moves along the extended axis of the ball screw 332 It includes a ball screw case 342 coupled with.

One end of the ball screw 332 is connected to the other end of the ball screw 331, and the rack and pinion 232 moves backward or forward according to rotation of the ball screw 332. A ball screw case 342 coupled to the pinion 230 is included.

The ball screw (331, 332) is a screw configured to feed the female screw in a straight line while the balls inside the nut move when the screw shaft rotates. In the ball screw, the driving torque is not extremely large as in the case of the slide screw, so that the axial clearance can be easily kept small. In addition, there is an advantage that the life is also increased due to less wear.

The ball screw cases 341 and 342 are coupled so that when the ball screws 331 and 332 rotate, the corresponding ball screw cases 341 and 342 move along the axis along which the ball screws 331 and 332 extend. In some embodiments, the ball screw cases 341 and 342 are installed along the diameter of the ball nut of the ball screw 331 and 332, and the length of the case may be longer than the length of the ball nut. For example, the ball screw cases 341 and 342 may be cylindrical cases surrounding the ball nut. In some other embodiments, the ball nuts of the ball screws 331 and 332 may be used as the ball screw cases 341 and 342 . In this case, as shown in FIG. 9 , the ball nut extends to the portion where the rack and pinion 130 and 230 are installed and is implemented to have a length coupled with the rack and pinion 130 and 230 .

As shown in FIG. 9 , when the ball screws 331 and 332 connect between the front wheel module 100 and the rear wheel module 200 and extend along the longitudinal axis of the vehicle, the ball screw cases 341 and 342 are formed at the front of the vehicle. Or you can move backwards.

One end of the ball screw 331 is connected to the third motor 301. One end of the ball screw 331 may be connected so that the ball screw 331 rotates in synchronization with the rotation of the third motor 301 . When the third motor 301 rotates, the ball screw 331 also rotates accordingly. When the ball screw 331 rotates, the ball screw case 341 also moves forward or backward of the vehicle.

One end of the ball screw 332 is connected to the other end of the ball screw 331, and when the ball screw 331 rotates, the ball screw 332 also rotates accordingly. Rotations of the ball screws 331 and 332 are synchronized with each other. When the ball screw 332 rotates, the ball screw case 342 also moves forward or backward of the vehicle.

In various embodiments of the present application, when the ball screw case 342 is synchronized with the ball screw 341 and the ball screw 331 rotates so that the ball screw case 341 moves in the first direction, the first direction It may be coupled to the ball screw 341 so as to rotate in a second direction opposite to the first direction. For example, the ball screw 331 and the ball screw case 341 are implemented as forward ball screws and their cases, and the ball screws 332 and ball screw cases 342 are implemented as reverse ball screws and their cases. can

In this coupling relationship, when the third motor 301 rotates in the first rotation direction, the ball screws 331 and 332 also rotate. When the ball screw 331 rotates, the ball screw case 341 moves in the rear direction of the vehicle, and the rack and pinion 130 also moves in the rear direction of the vehicle, as shown in FIG. 9A. Meanwhile, since the ball screw case 342 is coupled to move in the opposite direction to the ball screw case 341, when the ball screw 331 and the synchronizer ball screw 332 rotate, the ball screw as shown in FIG. 9A The case 342 moves in the forward direction of the vehicle and eventually the rack and pinion 230 also moves in the forward direction of the vehicle.

Meanwhile, when the third motor 301 rotates in the second rotation direction opposite to the first rotation direction, the ball screws 331 and 332 also rotate in the opposite direction to that shown in FIG. 9A. When the ball screw 331 rotates in the opposite direction to that of FIG. 9A, the ball screw case 341 moves in the forward direction of the vehicle and the rack and pinion 130 also moves in the forward direction of the vehicle, as shown in FIG. 9B. Due to the coupling structure between the ball screw case 342 and the ball screw 341, when the ball screw 332 rotates in synchronization with the ball screw 331, as shown in FIG. 9B, the ball screw case 342 moves to the rear of the vehicle. direction, and eventually the rack and pinion 230 also moves in the rearward direction of the vehicle.

The ball screw cases 341 and 342 are coupled to the rack and pinion 130 and 230. In various embodiments of the present application, the ball screw cases 341 and 342 may be coupled to the rack and pinion 130 and 230 at right angles. The rack and pinions 130 and 230 move in a horizontal state along the axial direction of the ball screws 331 and 332 .

The ball screw case 341 is coupled with the rack and pinion 130 so that the rack and pinion 130 moves forward or backward of the vehicle according to the rotation of the ball screw 331 . The ball screw case 342 is coupled with the rack and pinion 230 so that the rack and pinion 230 moves along the extended shaft according to the rotation of the ball screw 332 .

Due to the joints 141 and 142 coupled to both ends of the rack and pinions 130 and 230, the rack and pinions 130 and 230 respond to the movement of the ball screw cases 341 and 342 so that the ball screws 331 and 332 move. Move along the extended axis.

That is, when the third motor 301 rotates in the first rotation direction, the ball screw cases 341 and 342 and the rack and pinions 130 and 230 move to the center of the vehicle as shown in FIG. ) rotates in the second rotation direction opposite to the first rotation direction, it moves forward and backward of the vehicle again as shown in FIG. 9B.

In a state in which the front and rear wheels of the vehicle are aligned at a steering angle of 0° as shown in FIG. 1, the front links 151 and 152 and the rack and pinion 130 are arranged side by side with each other.

When the third motor 301 rotates, the rack and pinion 130 is easily moved by the joints 141 and 142 . When the rack and pinion 130 moves in a horizontal state toward the rear of the vehicle, one end of the front links 151 and 152 connected to the rack and pinion 130 in the front wheel module 100 is connected to the joints 141 and 142. ) and also moves by turning on the basis. The joints 161 and 162 are connected to the base frames 171 and 172 and the front link 151 so that the base frames 171 and 172 do not turn when the steering control force in the left or right direction of the rack and pinion 130 is not applied. , 152), even if the front links 151 and 152 move according to the rotation of the third motor 301, the base frames 171 and 172 do not turn with respect to the joints 161 and 162. The angle between the base frames 171 and 172 and the front links 151 and 152 is fixed. That is, when the rack and pinion 130 moves according to the rotation of the third motor 301, the angle between the base frames 171 and 172 and the front links 151 and 152 may remain fixed and not change. As a result, one end of the front links 151 and 152 moves toward the rear of the vehicle relatively more than the other ends of the front links 151 and 152 connected to the base frames 171 and 172, as shown in FIG. 9A. As shown, the front links 151 and 152 are arranged diagonally on the plane of the vehicle.

Similarly, when the third motor 301 rotates, the rack and pinion 230 easily moves by the joints 241 and 242 . When the rack and pinion 230 moves horizontally toward the front of the vehicle, the rear wheel module 200 pivots based on the joints 241 and 242 and connects the rear link 251 to the rack and pinion 230. 252) also moves. The joints 261 and 262 are connected to the base frames 271 and 272 and the rear link 251 so that the base frames 271 and 272 do not turn when the steering control force in the left or right direction of the rack and pinion 230 is not applied. , 252), even if the rear links 251 and 252 move according to the rotation of the third motor 301, the base frames 271 and 272 do not turn with respect to the joints 261 and 262. The angle between the base frames 271 and 272 and the rear links 251 and 252 is fixed. That is, when the rack and pinion 230 moves according to the rotation of the third motor 301, the angle between the base frames 271 and 272 and the rear links 251 and 252 may remain fixed and not change. As a result, one end of the rear links 251 and 252 moves toward the rear of the vehicle relatively more than the other ends of the rear links 251 and 252 connected to the base frames 271 and 272, as shown in FIG. 9A As shown, the rear links 251 and 252 are arranged diagonally on the plane of the vehicle. At this time, the rear links 251 and 252 and the front links 151 and 152 move in a diagonal arrangement symmetrical to each other.

On the other hand, when the third motor 301 rotates in the second rotation direction, which is opposite to the rotation direction of FIG. 252) are again arranged side by side as shown in FIG.

The controller 400 may cause the vehicle in which the steering system 1 is installed to perform a so-called zero-turn, turning operation in place by using rotational power of the third motor 301 .

FIG. 10 describes a situation of zero-turning by 180° according to the control operation of FIG. 9 , and FIG. 11 describes a situation of zero-turning by 90° according to the control operation of FIG. 9 .

10 and 11 , the controller 400 may transmit a 3-1 control command for causing the third motor 301 to rotate in the first rotation direction to the third motor 301 . Then, the third motor 301 rotates in the first rotation direction so that the front links 151 and 152 and the rear links 251 and 252 are symmetrical to each other as shown in FIG. 9A through the ball screws 331 and 332. The array structure is changed to a diagonal state of .

Subsequently, the controller 400 issues a forward control command for forward driving of the in-wheel motors 110 and 120 of the front wheels and/or the in-wheel motors 210 and 220 of the rear wheels in a state in which the arrangement structure is changed to the planar structure of FIG. 9A, or Transmits a reverse control command to drive in reverse. While the forward control command or the reverse control command continues, the driving motor operates so that the front/rear wheels may rotate forward or backward.

As shown in FIG. 10 , when the vehicle turns in place by 180°, the controller 400 stops transmission of a forward control command or a reverse control command to stop the vehicle. This 180° in-place turning operation makes it possible for the vehicle to drive next time while minimizing the travel distance without colliding with the surroundings in a narrow space with only one entrance like an elevator.

In addition, as shown in FIG. 11, when the vehicle turns in place by 90°, the controller 400 stops the transmission of a forward control command or a reverse control command to stop the vehicle, and the third motor 301 A 3-2 control command for rotating in the second rotation direction opposite to the first rotation direction is transmitted to the third motor 301, and the front links 151 and 152 arranged diagonally to each other and the rear The links 251 and 252 may be arranged parallel to the rack and pinions 130 and 230 . Such a 90° in-place turning operation makes it possible for the vehicle to drive next while minimizing the driving distance without colliding with the surroundings on a path with a narrow width where the turning operation of FIG. 4 or 6 is not possible, such as a right angle path. .

Embodiments of the present application may be variously changed. In some embodiments, the steering system 10 is configured such that the first motor 101 is installed farther from the center of the vehicle than the rack and pinion 130 and/or the second motor 201 is the rack and pinion 230 It can be changed to be installed farther from the center of the vehicle.

Then, the controller 400 may supply a control command for the steering operation of FIGS. 2, 3, 5, and 7 to the motors 101 and 201. In this case, the combination of control commands is also changed. For example, the 1-1 control command and the 2-1 control command may be supplied for a left turn. For right turn, the 1-2 control command and the 2-2 control command may be supplied.

In addition, the steering system 10 may be changed so that the third motor 301 is located at the rear of the vehicle and connected to the ball screw 341. Then, the controller 400 may supply the changed control command for the steering operation of FIG. 9 to the motor 301 .

It will be apparent to those skilled in the art that the steering system 10 may include other components. For example, the steering system 10 may include other hardware components necessary for the operations described herein, including input devices for data entry and output devices for printing or other data display.

According to another aspect of the present application, a vehicle steering method for efficiently driving a vehicle in various driving environments may be provided. The steering method may be performed by the steering system 10 . The steering control method may use an operation result according to an autonomous driving program linked to the steering system 10 .

12 is a flowchart of a steering method according to another aspect of the present application.

Referring to FIG. 12 , the steering method includes the steps of detecting an object around a driving path by a recognizing device and calculating an expected radius of curvature required for the vehicle when passing the corresponding driving path (S1210); Determining whether the calculated predicted radius of curvature of the vehicle is smaller than the first minimum radius of curvature according to the steering operation of the front wheel module 100 (S1220); If the expected radius of curvature is not smaller than the first minimum radius of curvature according to the steering operation of the front wheel module 100, whether the direction of the driving path after passing through the object is parallel to the direction of the driving path before passing through the object Determining step (S1221); When the direction of the driving route after passing the object is not parallel to the direction of the driving route before passing the object, the front wheel module 100 is used to rotate the vehicle to the front wheels by the controller 400 Controlling the steering operation of (S1222); and when the direction of the driving route after passing the object is parallel to the direction of the driving route before passing the object, the front wheel module 100 for the vehicle to drive diagonally by the controller 400, and and controlling the steering operation of the rear wheel module 200 (S1223).

An object, such as a wall or an obstacle, may collide with a vehicle when traveling along a driving path.

In the step S1210, the controller 400 or the autonomous driving program linked with the controller 400 may recognize the width and location of the object while detecting the object. The controller 400 may calculate an expected radius of curvature required when passing a corresponding driving route based on the result of self-recognition or the result of recognition provided from the autonomous driving program, and the horizontal length (vehicle width) and vertical length of the vehicle stored in advance. there is.

When the rack and pinion 130 is maximally controlled by the steering operation of the front wheel module 100, the controller 400 calculates a steerable radius of curvature as a first minimum radius of curvature based on the position of the vehicle close to the object. .

The controller 400 determines that the front wheel module 100 does not collide with an object even when driving with the front wheel steering when the expected radius of curvature is not smaller than the first minimum radius of curvature according to the steering operation of the front wheel module 100 . That is, the self-driving path around the object is a path driven by front-wheel steering. The controller 400 controls the front wheel module 100 of the vehicle to enable driving according to front wheel steering, and controls the vehicle to drive around without colliding with an object (S1221 and S1222).

In some embodiments, the controller 400 controls the operation of the other modules 200 and 300 except for the front wheel module 100 when the expected radius of curvature is not smaller than the first minimum radius of curvature according to the steering operation of the front wheel module 100. can be locked (S1222). At this time, the motor 201 of the rear wheel module 200 and the rack and pinion 230 are locked and do not operate the steering, and the motor 301 and the ball screws 331 and 332 of the longitudinal axis module 300 are also locked and do not drive. . The controller 400 increases the lifespan of components by preventing driving of unnecessary components when a collision does not occur even when the vehicle is driven only in front-wheel drive.

On the other hand, when the direction of the driving path after passing the object is parallel to the direction of the driving path before passing the object, the driving path may be a substantially straight driving path that does not travel straight only when avoiding the object. . In such a straight driving path, it is efficient to consume power when the speed drop is minimized.

In order to stably avoid obstacles even in high-speed driving conditions, when turning is unnecessary and the possibility of collision with obstacles is low, it is possible to quickly pass through an object by diagonal driving. Since the control operation for diagonal travel has been described above with reference to FIGS. 7 and 8 , a detailed description thereof will be omitted.

In addition, the steering method may include determining whether the calculated predicted radius of curvature of the vehicle is smaller than the second minimum radius of curvature according to the steering operation of the rear wheel module 200 (S1230); and when the calculated expected radius of curvature of the vehicle is smaller than the first minimum radius of curvature according to the steering operation of the front wheel module 100 and not smaller than the second minimum radius of curvature according to the steering operation of the rear wheel module 200, the controller 400 ), and controlling the steering operation of the front wheel module 100 and the steering operation of the rear wheel module 200 (S1231). As shown in FIG. 6 , the second minimum radius of curvature R2 is smaller than the first minimum radius of curvature R1.

The controller 400 steers when the rack and pinion 130 is maximally controlled by the steering motion of the front wheel module 100 and when the rack and pinion 230 is maximally controlled by the steering motion of the rear wheel module 200. A possible radius of curvature is calculated as the second minimum radius of curvature.

The controller 400 determines whether the expected radius of curvature is smaller than the first minimum radius of curvature according to the steering operation of the front wheel module 100 and not smaller than the second minimum radius of curvature according to the steering operation of the rear wheel module 200. , it is determined that there is a risk of colliding with an object while driving only with front wheel steering. That is, the self-driving path around the object is a path driven by 4-wheel steering. The controller 400 controls the front wheel module 100 and the rear wheel module 200 of the vehicle to enable driving according to the 4-wheel steering, and rotates with a turning radius greater than the first minimum radius of curvature without colliding with an object. The vehicle is controlled to drive around (S1231).

In some embodiments, the controller 400 determines that the expected radius of curvature is smaller than the first minimum curvature radius according to the steering operation of the front wheel module 100 and is smaller than the second minimum radius of curvature according to the steering operation of the rear wheel module 200. If the radius of curvature is not small, the operation of the modules 300 other than the modules 100 and 200 for four-wheel steering may be locked. At this time, the motor 301 and the ball screws 331 and 332 of the vertical axis module 300 are also locked and do not drive. The controller 400 increases the lifespan of components by preventing driving of unnecessary components when a collision does not occur even when the vehicle is driven only by four-wheel steering.

In addition, in the steering method, after the step (S1230), when the calculated predicted radius of curvature of the vehicle is smaller than the second minimum radius of curvature according to the steering operation of the rear wheel module 200, the controller 400 controls the object and controlling the front wheel module 100, the rear wheel module 200, and the longitudinal axis module 300 of the vehicle to turn in place at a position close to the object before passing (S1233).

If the expected radius of curvature is smaller than the second minimum radius of curvature according to the steering operation of the rear wheel module 200, the controller 400 determines that there is a risk of collision with an object while driving only with the 4-wheel steering. That is, the self-driving path around the object is a path that cannot be driven by 4-wheel steering.

As shown in FIG. 10 , the controller 400 may continue driving by turning in place at a position close to the object before passing the object. Since the control operation for turning in place has been described above with reference to FIGS. 9 and 10 , a detailed description thereof will be omitted.

When the steering system 10 is interlocked with an autonomous driving program, the steering system 10 recognizes the road environment with sensors such as cameras and lidars installed in a vehicle such as a driving robot and creates a driving route. Based on the vehicle dynamics model considering the minimum turning radius and width of the robot in steering mode, it is determined in real time whether driving and avoidance is possible, and the result of the determination is transmitted to the motor drive to actively control the angle and speed of the motor. there is.

The steering system 10 satisfies the need for a mechanism that can respond immediately to the situation because it is important to flexibly drive in various environments such as sidewalks, buildings, elevators, and narrow alleys in indoor and outdoor autonomous driving environments. can do. The steering system 10 has the advantage of being able to pass through a narrow door more stably because it can travel after matching the horizontal and vertical directions rather than turning, especially when passing through a narrow door such as entering an elevator.

In addition, according to the steering control method performed by the steering system 10, a steering operation suitable for a driving environment is selectively allowed, thereby minimizing the driving of components unnecessary for achieving a collision-free driving result. Thus, the steering system 10 can increase the lifespan of

In the case of implementing the embodiment of the present invention using hardware, ASICs (application specific integrated circuits) or DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices) configured to perform the present invention , FPGAs (field programmable gate arrays), etc. may be provided in the processor of the present invention.

Meanwhile, the above-described invention can be written as a program that can be executed on a computer, and can be implemented in a general-purpose digital computer that operates the program using a computer-readable medium. In addition, the structure of data used in the above-described method may be recorded on a computer-readable storage medium through various means. Program storage devices, which may be used to describe a storage device containing executable computer code for performing various methods of the present invention, should not be construed as including transitory objects such as carrier waves or signals. do. The computer-readable storage media includes storage media such as magnetic storage media (eg, ROM, floppy disk, hard disk, etc.) and optical reading media (eg, CD-ROM, DVD, etc.).

The embodiments described above are those in which elements and features of the present invention are combined in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented in a form not combined with other components or features. In addition, it is also possible to configure an embodiment of the present invention by combining some elements and/or features. The order of operations described in the embodiments of the invention may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is obvious that claims that do not have an explicit citation relationship in the claims can be combined to form an embodiment or can be included as new claims by amendment after filing.

It will be clear to those skilled in the art that the present invention can be embodied in other forms without departing from the technical spirit and essential characteristics of the present invention. Accordingly, the above embodiments should be considered in all respects as illustrative rather than restrictive. The scope of the present invention should be determined by reasonable interpretation of the appended claims and all possible changes within the equivalent scope of the present invention.

Claims (13)

In a steering system installed in a vehicle having front and rear wheels,
A front wheel module 100 configured to steer the front wheels of the vehicle through rotational power of a first motor 101;
A rear wheel module 200 configured to steer the rear wheels of the vehicle through rotational power of a second motor 201;
A longitudinal axis module 300 configured to connect the front wheel module 100 and the rear wheel module 200 and to steer the left and right wheels of the front wheel and the left and right wheels of the rear wheel of the vehicle respectively through the rotational power of the third motor 300 , and
A controller 400 for controlling first to third motors and a drive motor that provides rotational power to at least one of the front and rear wheels,
steering system.
The method of claim 1, wherein the front wheel module 100,
A rack and pinion installed between the left wheel 11 and the right wheel 12 of the front wheel and having a rack 131 moving to the left or right by the rotational power of the first motor 101 to steer the front wheel ( 130),
The front links 151 and 152 connected to one end of the front links 151 and 152 through both ends of the rack and pinion 130 and joints 141 and 142;
Base frames 171 and 172 supporting the left wheel 11 and the right wheel 12 of the front wheels connected to the other ends of the front links 151 and 152 through joints 161 and 162,
The rear wheel module 200,
A rack and pinion 230 having a rack 231 installed between the left wheel 21 and the right wheel 22 of the rear wheel and moving to the left or right by the rotational power of the second motor 201 to steer the rear wheel. ),
The rear links 251 and 252 connected to one end of the rear links 251 and 252 through both ends of the rack and pinion 230 and joints 241 and 242;
Base frames 271 and 272 supporting the left wheel 21 and the right wheel 22 of the rear wheel connected to the other ends of the rear links 251 and 252 through joints 261 and 262,
The joints 161 and 162 are the front links 151 and 152 and the base frames 171 and 172 so that the rack 131 turns in relation to the coupling axis when a steering control force generated by moving the rack 131 in the left or right direction is applied. combined with,
The joints 261 and 262 are connected to the rear links 251 and 252 and the base frames 271 and 272 so that the rack 231 pivots with respect to a coupling axis when a steering control force generated by moving the rack 231 in the left or right direction is applied. Characterized in that it is combined with,
steering system.
According to claim 2,
The controller 400, in order to control the vehicle to turn left,
The first motor 101 rotates in a first rotational direction to supply a 1-1 control command to move the rack 131 in a leftward direction to the first motor 101, and
In order to control the vehicle to turn right, the first motor 101 rotates in a second rotation direction opposite to the first rotation direction, so that the rack 131 moves in the right direction. Characterized in that it is configured to supply a command to the first motor (101),
steering system.
According to claim 3,
The controller 400 reduces the left turning radius of the vehicle compared to when only the front wheels or only the rear wheels are steered.
The second motor 201 rotates in the second rotation direction to supply a 2-2 control command to move the rack 231 in the left direction to the second motor 201, and
So that the right turning radius of the vehicle is reduced compared to when only the front wheels are steered or only the rear wheels are steered,
Characterized in that the second motor 201 rotates in the second rotation direction to supply a 2-1 control command to the second motor 201 to move the rack 231 in the right direction. doing,
steering system.
According to claim 2,
The controller 400, in order for the vehicle to drive in the left diagonal direction,
The first motor 101 rotates in a first rotation direction to supply a 1-1 control command to move the rack 131 in a left direction to the first motor 101,
The second motor 201 rotates in the second rotation direction, which is opposite to the first rotation direction, so that the 2-2 control command for moving the rack 131 in the right direction is transmitted to the second motor 201. supply to, and
In order to control the vehicle to drive in the right diagonal direction,
The first motor 101 rotates in the second rotation direction to supply a 1-2 control command to the first motor to move the rack 131 in the right direction,
The second motor 201 is configured to rotate in the first rotation direction to supply a 2-1 control command to the second motor 201 to move the rack 131 in the left direction,
The steering angle according to the 1-1 control command and the steering angle according to the 2-2 control command are parallel to each other,
Characterized in that the steering angle according to the 1-2 control command and the steering angle according to the 2-1 control command are parallel to each other,
steering system.
According to claim 2,
The joints 141 and 142 do not turn based on the coupling axis when the rack 131 moves in the left or right direction, and the steering control force according to the movement of the rack 131 is applied through the front links 151 and 152. Combined with the rack and pinion 130 and the front links 151 and 152 to be transmitted to the base frames 171 and 172
The joints 241 and 242 do not turn based on the coupling axis when the rack 231 moves in the left or right direction, and the steering control force according to the movement of the rack 231 is applied to the base frame through the rear links 251 and 252. Characterized in that it is combined with the rack and pinion 230 and the rear links 251 and 252 to transmit to (271 and 272),
steering system.
The method of claim 6, wherein the longitudinal axis module 300,
The ball screw 331 coupled with the third motor 301 so that the ball screw 331 rotates according to the rotational power of the third motor 301,
When the ball screw 331 rotates, a ball screw case 341 coupled with the ball screw 331 moves along an extended axis - the ball screw case 341 is the ball screw ( 331) is coupled with the rack and pinion 130 so that the rack and pinion 130 moves along the extended axis,
The ball screw 332 coupled so that the ball screw 332 rotates according to the rotation of the ball screw 331,
When the ball screw 332 rotates, the ball screw 332 moves along an extended axis, and the ball screw case 342 coupled with the ball screw 332 - the ball screw case 342 is the ball screw ( 332) coupled with the rack and pinion 230 so that the rack and pinion 230 moves along the extended axis according to the rotation of 332).
steering system.
According to claim 7,
The rack and pinion (130, 230) is coupled in a perpendicular state to the extension axis of the ball screw (331, 332),
When the third motor 301 rotates in the first rotation direction,
In the front wheel module 100, the base frames 171 and 172 do not turn based on the joints 161 and 162, and the angle between the base frames 171 and 172 and the front links 151 and 152 is fixed, and the rack and As one end of the front links 151 and 152 connected to the pinion 130 pivots and moves with respect to the joints 141 and 142, the front links 151 and 152 are arranged diagonally on the plane of the vehicle, ,
In the rear wheel module 200, the base frames 271 and 272 do not turn based on the joints 261 and 262, and the angle between the base frames 271 and 272 and the rear links 251 and 252 is fixed, and the rack and One ends of the rear links 251 and 252 connected to the pinion 230 pivot and move with respect to the joints 241 and 242, so that the rear links 251 and 252 move on the plane of the vehicle. 151, 152) and symmetrically arranged diagonally,
steering system.
The method of claim 8, wherein the controller 400 controls the vehicle to turn in place,
Transmitting a 3-1 control command for causing the third motor 301 to rotate in a first rotation direction to the third motor 301,
Characterized in that the arrangement structure of the front links 151 and 152 and the rear links 251 and 252 is configured to transmit a forward control command or a reverse control command to the drive motor in a state in which the arrangement structure is arranged diagonally to each other,
steering system.
The method of claim 9, wherein the controller 400,
Stopping the transmission of the forward control command or the reverse control command to stop the vehicle when the vehicle turns in place by 90°, and
In order to arrange the front links 151 and 152 and the rear links 251 and 252 arranged diagonally with each other in parallel with the rack and pinion 130 and 230, the third motor 301 rotates in the first rotational direction. Characterized in that it is further configured to transmit a 3-2 control command to rotate in the second rotation direction, which is the opposite direction, to the third motor 301,
steering system.
In an autonomous vehicle equipped with a steering system according to any one of claims 1 to 10,
It includes at least one pair of in-wheel motors (110, 120, 210, 220) installed on at least one of the left and right wheels of the front and rear wheels, and the base frame (171, 172, 271, 272) is the in-wheel motor (110, 272). 120, 210, 220) characterized in that coupled to,
self-driving vehicle.
A steering method performed by a steering system according to any one of claims 1 to 10,
detecting objects around the driving route by the recognition device and calculating an expected curvature radius required for the vehicle when passing the corresponding driving route (S1210);
Determining whether the calculated predicted radius of curvature of the vehicle is smaller than the first minimum radius of curvature according to the steering operation of the front wheel module 100 (S1220);
If the expected radius of curvature is not smaller than the first minimum radius of curvature according to the steering operation of the front wheel module 100, whether the direction of the driving path after passing through the object is parallel to the direction of the driving path before passing through the object Determining step (S1221);
When the direction of the driving route after passing the object is not parallel to the direction of the driving route before passing the object, the front wheel module 100 is used to rotate the vehicle to the front wheels by the controller 400 Controlling the steering operation of (S1222); and
When the direction of the driving route after passing through the object is parallel to the direction of the driving route before passing through the object, the controller 400 controls the front wheel module 100 and the rear wheel so that the vehicle travels diagonally. Including controlling the steering operation of the module 200 (S1223),
steering method.
The method of claim 12, wherein the steering method,
Determining whether the calculated predicted radius of curvature of the vehicle is smaller than the second minimum radius of curvature according to the steering operation of the rear wheel module 200 (S1230);
When the predicted radius of curvature of the calculated vehicle is smaller than the first minimum radius of curvature according to the steering operation of the front wheel module 100 and not smaller than the second minimum radius of curvature according to the steering operation of the rear wheel module 200, the controller 400 Controlling the steering operation of the front wheel module 100 and the steering operation of the rear wheel module 200 by (S1231); and
After the step (S1230), if the predicted radius of curvature of the vehicle is smaller than the second minimum radius of curvature according to the steering operation of the rear wheel module 200, the controller 400 determines the object before passing the object. Further comprising the step of controlling the front wheel module 100, the rear wheel module 200, and the longitudinal axis module 300 of the vehicle to turn in place at a close position (S1233),
Characterized in that the second minimum radius of curvature is smaller than the first minimum radius of curvature,
steering method.

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